It seems the web socket implementation doesn't acknowledge ping control frames. I noticed the WebSocketContext API exposes a pong() method, but the RFC indicates that you must pong with the same exact message from the received ping. I see no way to listen for these types of control frames in order to be able to respond.

I've been playing around with resin-4.0.38 and when hitting my web app in Chrome, the websocket gets disconnected after 2 minutes due to the server not acknowledging a ping request with a pong.